1. Field of the Invention
The present invention relates to neurological diagnostic and therapeutic medical devices, and, more particularly, to a neural sensing device with a plurality of microprobes useful for collecting bio-electrical signals and a method for making the same.
2. Description of the Related Art
Conventional neural sensing devices for use in recording and measuring electrical activity of the brain, such as those used in electroencephalography (EEG), include a plurality of microprobes, each having a metal needle or a needle coated with a metal layer. The microprobes are utilized to penetrate the skin of the scalp to collect bio-electrical signals from a patient.
Skin is a layered structure, including two primary layers: the epidermis, which provides waterproofing and serves as a barrier to infection; and the dermis, which serves as a location for the appendages of the skin. The epidermis can be roughly divided into another two layers: the stratum corneum and the stratum germinativum. The stratum corneum includes dead skin cells, and, therefore serves as a waterproof barrier layer. The stratum germinativum comprises living cells and provides good electrical conductivity. Unfortunately, conventional neural sensing devices tend to be affected by undesired noise through the portions of the microprobes in the stratum corneum.